1-{[2-(Cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dialkoxy-2-pyrimidinyl) urea compounds which are useful as crop-selective herbicidal agents are disclosed in U.S. Pat. Nos. 5,009,699 and 5,280,007. In particular, 1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidiny l)urea is being developed as a herbicide for control of a wide range of dicot and sedge weed species infesting cereals and rice. Additionally, 1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidiny l)urea binds tightly to soil and would not be expected to pose a threat to groundwater by leaching from soil. Further, 1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidiny l)urea has been shown to be very safe for mammals and other non-target organisms.
Since 1-{[2-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6 -dialkoxy-2-pyrimidinyl)urea compounds are highly active, crop-selective herbicidal agents and are environmentally benign, there is ongoing research to discover and develop effective and efficient processes for their manufacture.
U.S. Pat. No. 4,401,816 discloses sulfamoyl chlorides which are useful in the preparation of sulfamides and pyrrole sulfonamides. However, that patent does not disclose a process for the preparation of sulfamoyl urea compounds.
U.S. Pat. No. 3,939,158 discloses N-(2,4-dihalo-s-triazin-6-yl)ureas and a process for their manufacture. However, the patentee does not describe a process for the preparation of sulfamoyl urea compounds.
It is therefore an object of the present invention to provide an effective and efficient process for the manufacture of 1-{[2-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dialkoxy-2-pyrimidinyl )urea compounds.
It is also an object of the present invention to provide intermediate compounds which are useful in the process of the present invention.